iommu-fixes-v5.8-rc2

A couple of Intel VT-d fixes:

	- Make Intel SVM code 64bit only. The code uses pgd_t* and the
	  IOMMU only supports long-mode page-table formats, so its
	  broken on 32bit anyway.

	- Make sure GFX quirks in for Intel VT-d are not applied to
	  untrusted devices. Those devices might gain full memory access
	  otherwise.

	- Identity mapping setup fix.

	- Fix ACS enabling when Intel IOMMU is off and untrusted devices
	  are detected.

	- Two smaller fixes for coherency and IO page-table setup